1. Field of the Invention
The present invention is directed to an apparatus for filtering high frequency products generated by and present in the ground circuits of digital devices such as CD players.
More particularly, the invention is directed to a filter for use in high accuracy audio systems for eliminating high frequency products present in the ground circuit of the digital device from being transmitted to the amplification circuitry.
2. The Prior Art
It is known that digital devices employing "clock" circuits are a source of high frequency products which, while above the audible range, modulate the audible frequencies producing harmonics which degrade the accuracy of reproduction of audible signals.
In my copending application Ser. No. 07-700,394, now U.S. Pat. No. 5,115,368, there is disclosed an AC power strip for use with a device incorporating digital switching circuitry such as a CD player or DAT recorder, which isolates amplification equipment etc. from digitally generated high frequency products injected into the mains line by the digital circuitry. I have determined that substantial additional degradation of reproduced sound occurs as a result of high frequency products from digital sources being conducted from the digital source to amplification equipment via the interconnects linking such components.
More particularly, while the "positive" or "hot" signals of digital equipments are generally free of noise generated by the digital device, the ground circuits are replete with such noise components.
While some of the latest high fidelity componentry employs so-called "balanced" interconnect systems wherein both the positive and negative leads are isolated from ground circuitry and thus from digital noise, the vast majority of currently available equipment does not employ balanced technology, with resultant transmission via interconnects of the digital noise products.